Mercury/Mars combines Mercury's association with speech, gestures, thought, and communications of all types with Mars' association with assertiveness, bravery, and war:
A comical take on the brave and assertive (Mars) speech (Mercury) of the Mercury/Mars combination can be seen in the following clip, in which actress Christina Ricci demonstrates the Mercury/Mars combination in her natal chart in the role of Wednesday in the movie Addams Family Values: https://www.youtube.com/watch?v=oxWOdXtLSBo
To understand the Mercury/Mars combination let’s look at the life of celebrity Joe Rogan. He is a stand up comic. He is a commentator for the Ultimate Fighting Championship. He interviews intellectuals on one of the most popular podcasts in the world. So, what is his job? What does he do? It’s hard to sum it up in one title. Yet, when we look at his astrological birth chart it all makes perfect sense. He was born with Mercury and Mars in alignment. Mercury symbolizes the voice, speaking, the mind. Mars heats up and activates whatever it is in alignment with, adding athleticism and warrior-like bravery. His role as a commentator (Mercury) for the Ultimate Fighting Championship (Mars) is an easy match to spot for this combination. Yet stand up comedy is too, in that bravery (Mars) is required to entertain a live audience with one’s voice (Mercury). If you listen to his podcast, sooner or later you will realize that you are basically listening to Joe Rogan exercise (Mars) his mind (Mercury) in public. The podcast is a way to capitalize on intellectual discussions he’d probably be taking on anyway.